Schaudt DT220 12volts not switching on,Help !

Want to head to Europe this week,so got my van out of storage and the 12volts won't switch on from my control panel.Its a Frankia A class with the Schaudt DT220 and EBL220-4,any help would be appreciated.

Panic over,put it down to a senior moment.I thought when swicthing back on you just pressed it twice,when you have to press and hold it the second time. Thanks for the replies,i had typed the bit up to the emoji then didn't post as SWMBO arrived home.The van has been in storage since the beginning of July and just forgot the procedure.